FöHN WIND

A 'föhn wind' or 'foehn wind' occurs when a deep layer of prevailing wind is forced over a mountain range (Orographic lifting). As the wind moves upslope, it expands and cools, causing water vapor to precipitate out. This dehydrated air then passes over the crest and begins to move downslope. As the wind descends to lower levels on the leeward side of the mountains, the air temperature increases adiabatically as it comes under greater atmospheric pressure creating strong, gusty, warm and dry winds. Föhn winds can raise temperatures by as much as 30°C (54°F) in just a matter of hours. Winds of this type are called "snow-eaters" for their ability to make snow melt rapidly. This ability is based not only on high temperature, but also the low relative humidity of the air mass. Föhn winds are also associated with the rapid spread of wildfires, making some regions which experience these winds particularly fire-prone.
The name ''föhn'' (from the German ''Föhn'', pronounced ) originated in the Alps and central Europe enjoys a warmer climate due to them. Föhn winds are notorious among mountaineers in the Alps, especially those climbing the Eiger, for whom the winds add additional difficulty in ascending an already difficult peak.
AEG registered the trademark ''Fön'' in the 1920s for its hairdryer, which is widely used as a synonym in several languages, such as German, Italian, Dutch, Romanian, Swedish, Turkish and French in western Switzerland.
These winds are often associated in popular mythology with illness ranging from migraines to psychosis. The Santa Ana winds are often called "the murder winds". A study by the Ludwig-Maximilians-Universität München found that suicide and accidents increased by 10 percent during föhn winds in Central Europe. The causation of Föhnkrankheit (English: Föhn-sickness), however, remains to be proven.
Regionally, these winds are known by many different names. These include:

★ Zonda winds in Argentina

★ Chinook winds in the Rocky Mountains, United States/Canada and the Chugach Mountains of Alaska, United States

★ Diablo winds in the San Francisco Bay Area, United States

★ Santa Ana winds in Southern California, United States

★ The Nor'wester in Canterbury and Otago, New Zealand

★ Halny in the Carpathian Mountains, Eastern Europe

★ Fogony in the Catalan Pyrenees

★ Bergwind in South Africa

★ Viento Sur in the Cantabrian region (northern Spain)

★ Terral in Málaga (southern Spain)

★ Föhn in Austria, southern Germany and German language parts of Switzerland

Contents

Trivia

See also

References

External links

Trivia

The föhn plays an important part in Dario Argento's film Phenomena

See also

★ Katabatic winds

★ Chinook wind

★ Rain shadow

References

★ McKnight, TL & Hess, Darrel (2000). Foehn/Chinoonk Winds. In , ''Physical Geography: A Landscape Appreciation'', pp. 132. Upper Saddle River, NJ: Prentice Hall. ISBN 0130202630

External links

★ Illustration